The present invention relates to a boat and, more particularly, to an improved construction of a buoyant boat having a girder box support structure and relatively rigid topsides which perform a buoyancy function.
A number of aquatic vessels have been proposed and developed for use in military, commercial and recreational applications. In many conventional boats, the topsides are formed from the same rigid material as the hull. This imposes limitations on the versatility of the boat structure. Indeed, it has long been the desire of boat designers and builders to provide boats which are modular, that is formed from parts which may be manufactured at different times and/or from different materials having desired characteristics, so that the particular needs of various consumers can be accommodated. Thus, one trend has been to form the topsides of aquatic vessels from inflatable structures which are disposed around and about the periphery of the rigid hull or rigid hull portion. The inflatable structure or structures are air-containing vessels which typically are made of supported rubber or unsupported plastic film adhesively and/or mechanically secured to the rigid structure. Mechanical fasteners, however, have the disadvantage that they necessarily concentrate stress between the rigid and flexible hull portions at points and thus increase the probability of failure of the material and/or the fastening structure at those points of attachment.
Inflatable boat structures have been proposed by me in earlier U.S. patents cited herein below wherein the inflatable portions of the boat are encased within shrouds so as to increase the durability or versatility of the rigid inflatable boat and to facilitate assembly, disassembly, repair, and replacement of parts of the structure. The inclusion of bolt ropes with the shrouds further provides a line rather than points of attachment thereby further increasing the versatility and utility of the design. One construction, disclosed in my prior art U.S. Pat. No. 4,498,413, the disclosure of which is incorporated herein by this reference, involves the use of an inflatable bladder or a plurality of such bladders inside a shroud and arranged around and above the periphery of a rigid bottom module. The shroud may be removably attached to the rigid bottom module by means of a bolt rope as disclosed in my prior U.S. Pat. No. 4,660,497, the disclosure of which is incorporated herein by this reference. Thus, the resulting aquatic vessel is modular. Another modular rigid inflatable boat is disclosed in my earlier U.S. Pat. No. 4,724,792, the disclosure of which is incorporated herein by this reference.
Yet a further boat structure developed by me is disclosed in U.S. Pat. No. 4,928,619, the disclosure of which is incorporated herein by this reference, which relates, in particular, to the bottom portions of a boat wherein the deck part and the hull part are interconnected about the periphery of the boat structure by shroud-incased buoyant elements so that, preferably, the hull to deck joint typically provided peripherally of a hull part and a deck part can be eliminated. Thus, in the foregoing structure, the rigid bottom was one module, the shroud another module, and the bladder or bladders is or are another module. The bladders may be attached and/or positioned by provision through the shroud.
All boats made according to the aforementioned disclosures are, of course, unique and advantageous. That is not to say, however, that improvement thereof is not possible and indeed the present invention constitutes an improvement of my prior aquatic vessel structures.
In accordance with the specifically disclosed embodiments of the above-referenced patents, the buoyancy function, that is the function of preventing water from entering the boat, is preferably preformed by inflatable topsides which are most preferably formed from one or more bladder elements encased in a shroud. While such structures have the advantage of resilient topsides, compact storage, and interchangeable parts, such an inflatable structure requires assembly and inflation prior to use of the vessel, requires a source of fluid such as air under pressure to inflate the inflatable bladders, and is susceptible to puncture. Furthermore, the cross-sectional shape of inflatable topsides is necessarily limited to a circle.
Thus, despite the trend toward inflatable topsides, there remains a desire in the industry to provide a modular boat structure which provides the advantages of relatively resilient topsides without the disadvantages of inflatable topsides noted above.